What Makes a Secure Password?
In today's digital landscape, strong passwords are your first line of defense against unauthorized access to your accounts and personal information. A secure password isn't just about using random characters—it incorporates several key elements to maximize protection.
🔢 Sufficient Length
Length is one of the most critical factors in password security. Modern security experts recommend a minimum of 12-16 characters, with longer passwords providing exponentially better protection against brute force attacks. Each additional character significantly increases the number of possible combinations a hacker would need to try.
🔀 Complexity
Complex passwords mix different character types: uppercase letters, lowercase letters, numbers, and special symbols (@#$%^&*!). This diversity increases the "character space" of your password, making it much harder to crack through brute force or dictionary attacks. Avoiding common substitutions (like "p@ssw0rd") is also important, as these are well-known to attackers.
🎲 Randomness
Truly random passwords resist all types of pattern-based attacks. Human-generated "random" strings often contain unconscious patterns that can be exploited. Using a reliable random password generator (like this tool) provides true randomness that eliminates predictable sequences. The higher the entropy (randomness), the stronger the password.
⚠️ Uniqueness
Using a unique password for each account is crucial. Even a strong password becomes a security risk if reused across multiple sites—a breach on one site could compromise all your accounts. Each generated password should be used for only one account or service. Password managers help you maintain different strong passwords for every account.
Using Our Password Generator
- Set Password Length: Use the slider to choose a length between 8 and 64 characters. While 8 characters is the minimum, we recommend at least 16 characters for better security. Longer passwords provide exponentially greater protection.
- Select Character Types: Choose which character types to include:
- Uppercase letters (A-Z): Including uppercase letters adds 26 more possible characters.
- Lowercase letters (a-z): The basic foundation of most passwords.
- Numbers (0-9): Adding numbers significantly improves password strength.
- Symbols (!@#$%^&*...): Special characters greatly increase password complexity.
For maximum security, we recommend enabling all character types. Each additional character set exponentially increases the difficulty of cracking your password.
- Advanced Options (Optional): Click "Show Advanced Options" to access additional settings:
- Exclude similar characters: Removes easily confused characters like 1, l, I, 0, O, etc.
- Exclude ambiguous characters: Removes symbols that may be problematic in some systems.
- Exclude specific characters: Manually specify any characters you want to exclude.
These options are helpful when creating passwords for systems with specific character limitations or to improve readability.
- Generate Password: Click the "Generate New Password" button to create a random password with your chosen settings. You can generate as many passwords as you like until you find one that meets your needs.
- Check Password Strength: The tool automatically evaluates the generated password's strength, showing:
- Very Weak: Highly vulnerable to brute force attacks
- Weak: Can be cracked within reasonable time
- Moderate: Offers basic protection against common attacks
- Strong: Difficult to crack with current technology
- Very Strong: Extremely resistant to cracking attempts
- Copy and Save: Use the copy button to copy the password to your clipboard. You can also save the password to your local browser storage using the "Save Password" button for future reference.
Important Security Notes:
- Privacy: All passwords are generated locally in your browser. We never see, store, or transmit your passwords.
- Saved Passwords: Passwords saved using the "Save Password" feature are stored only on your local device using your browser's localStorage feature. They're never sent to our servers.
- Password Managers: For managing multiple passwords securely, consider using a dedicated password manager like LastPass, 1Password, Bitwarden, or KeePass.
- Copy with Care: When copying passwords, be aware of what applications might have clipboard access on your device.
Password Strength: Understanding the Science
Password strength is determined by how resistant your password is to various cracking methods. Modern password strength evaluation uses the concept of entropy—a measure of unpredictability or randomness.
Entropy and Password Strength
Entropy is measured in bits, where each bit doubles the number of possible combinations. A password with 40 bits of entropy has 240 (or about 1 trillion) possible combinations.
The formula for calculating password entropy is:
Entropy (bits) = Log2(CL)
Where:
- C = Size of the character set (e.g., 26 for lowercase letters only, 95 for all printable ASCII characters)
- L = Length of the password
Strength Categories
| Strength | Entropy (bits) | Example | Time to Crack* |
|---|---|---|---|
| Very Weak | <28 bits | dog123 | Seconds to minutes |
| Weak | 28-35 bits | password1 | Hours to days |
| Moderate | 36-59 bits | Tr0ub4dor | Months to years |
| Strong | 60-79 bits | P@55w0rd!2Fh&K | Centuries |
| Very Strong | 80+ bits | 3pZU^K9r&FDX!q2VmBnE | Beyond foreseeable technology |
* Time to crack estimates assume sophisticated attackers with advanced hardware. Actual times vary based on attacker resources and methods.
Real-World Examples
Here's how different password types compare in terms of entropy:
- 8 lowercase letters: abcdefgh~38 bits
- 8 mixed-case letters: aBcDeFgH~47 bits
- 8 mixed chars: aB3$Ef!h~53 bits
- 12 mixed chars: aB3$Ef!h9*kL~79 bits
- 16 mixed chars: aB3$Ef!h9*kL7@pQ~105 bits
Note that increasing password length has a much greater impact on security than simply adding more character types. A longer password using only lowercase letters can be more secure than a shorter one with mixed characters.
Password Security Best Practices
🔑 Use Unique Passwords for Every Account
One of the most critical security practices is using a different password for each account. Password reuse means that a breach on one site compromises all your accounts with the same password. Data breaches happen regularly—even to major companies—so using unique passwords ensures that damage is contained to a single account.
🔄 Change Passwords Regularly (But Strategically)
While conventional wisdom suggests changing passwords every few months, modern security experts have revised this advice. Instead of regular changes, focus on:
- Changing passwords immediately after a known breach
- Updating passwords for your most sensitive accounts (financial, email) annually
- Replacing weak passwords with stronger ones whenever possible
Frequent mandatory password changes can backfire by encouraging simpler passwords and patterns (like incrementing numbers).
📱 Enable Two-Factor Authentication (2FA)
Even the strongest password provides only one layer of protection. Two-factor authentication adds a second verification step—typically something you have (like a mobile device) in addition to something you know (your password). This extra layer means that even if someone obtains your password, they still can't access your account without the second factor.
Whenever possible, enable 2FA on your accounts, especially for email, financial services, and social media.
💾 Use a Password Manager
Password managers are specialized tools designed to securely store, generate, and autofill your passwords. They offer significant advantages:
- Store hundreds of unique, complex passwords
- Generate strong random passwords on demand
- Fill passwords automatically (reducing phishing vulnerability)
- Sync across multiple devices securely
- Alert you to weak or reused passwords
With a password manager, you only need to remember one master password, while all your other passwords can be long, complex, and unique without the burden of memorization.
⚠️ Avoid Common Password Patterns
Even when creating complex passwords, avoid these common patterns that reduce security:
- Simple word + number combinations (dog123, password1)
- Keyboard patterns (qwerty, 12345, asdfgh)
- Personal information (birthdays, names, addresses)
- Simple character substitutions (p@ssw0rd, s3cur1ty)
- Common phrases or song lyrics
- Sports teams or popular cultural references
These patterns are well-known to attackers and are included in their cracking dictionaries.
Handling Password Requirements
Many websites and services impose specific password requirements that can sometimes be challenging to meet. Our password generator can help you navigate these requirements through its customization options.
Common Password Requirements
| Requirement | How to Handle It |
|---|---|
| Minimum length | Use our length slider to set the appropriate password length |
| Maximum length | Keep password under the limit (shorten if necessary) |
| Required character types | Enable the checkboxes for required character types (uppercase, lowercase, numbers, symbols) |
| Prohibited characters | Use the "Exclude specific characters" option in advanced settings |
| No ambiguous characters | Enable "Exclude ambiguous characters" in advanced settings |
Strategies for Specific Systems
Banking & Financial Sites
- Often limited to 8-12 characters
- May prohibit special characters
- Sometimes restrict to alphanumeric
- Solution: Use maximum allowed length with mix of uppercase, lowercase, and numbers
Legacy Systems
- May have character type restrictions
- Often prohibit certain special characters
- May have shorter maximum lengths
- Solution: Use "Exclude specific characters" and focus on length where possible
Mobile Entry Systems
- Password will be typed on mobile keyboards
- Special characters require extra taps
- Solution: Consider excluding ambiguous characters and focusing on length
Security-Critical Systems
- Usually accept longer passwords
- Often require all character types
- Solution: Use maximum length with all character types enabled
When You Can't Control the Requirements
When faced with systems that enforce password policies that reduce security (like short maximum lengths or character restrictions), consider these mitigation strategies:
- Use the maximum allowed length
- Enable as many character types as permitted
- Enable additional security features like 2FA if available
- Consider using a different service if security is critical and options are severely limited
Frequently Asked Questions
Are passwords generated by this tool truly random?
Yes, our password generator uses cryptographically secure random number generation provided by your browser's built-in cryptography functions. This ensures high-quality randomness for maximum security. However, true randomness on computers is a complex topic—we use the best available methods to ensure strong, unpredictable passwords.
How secure is the "Save Password" feature?
The Save Password feature stores passwords only in your browser's localStorage, which means they never leave your device and are not transmitted over the internet. However, this storage is not encrypted—anyone with access to your device could potentially access saved passwords. For maximum security, we recommend using a dedicated password manager for long-term storage.
Why do some websites limit password length or character types?
Many websites limit password complexity due to:
- Legacy systems with technical limitations
- Outdated security practices
- Misguided attempts to reduce user frustration
- Inadequate database encryption methods
These limitations are generally considered poor security practice by modern standards, but users often have no choice but to work within them.
How can I remember complex passwords?
The short answer: you shouldn't try to remember many complex passwords. Instead:
- Use a reputable password manager to securely store your passwords
- Create a few strong, memorable passwords for critical accounts like your password manager and email
- For these critical passwords, consider using the passphrase method (string of random words)
Modern security best practices acknowledge that using a password manager is more secure than trying to memorize dozens of unique passwords.
What makes a password "strong" vs "very strong"?
In our tool, a "strong" password typically has 60-79 bits of entropy, while "very strong" has 80+ bits. The difference is mainly about future-proofing:
- Strong passwords resist current cracking methods and should be secure for many years under normal circumstances
- Very strong passwords provide protection against future advances in computing power and quantum computing
For most everyday purposes, a "strong" password offers adequate protection. "Very strong" is recommended for your most critical accounts and those you may maintain for many years.
Are passphrases better than random passwords?
Both approaches have merits:
- Random passwords (like "p7X$r2tK!9Bv") offer high entropy in a compact form and are excellent when using password managers
- Passphrases (like "correct horse battery staple") are easier to remember while still providing good security if long enough
For passwords you must memorize, a long passphrase (5+ random words) can be both secure and memorable. For passwords you'll store in a password manager, fully random passwords are typically more secure for the same length.